title: Effectiveness of Rose Bengal test and fluorescence polarization assay in the diagnosis of Brucella spp. infections in free range cattle reared in endemic areas in Zambia.
abstract: The effectiveness of Rose Bengal test (RBT) and fluorescence polarization assay (FPA) in diagnosing cattle brucellosis in endemic areas was assessed and RBT and FPA test agreement was compared (n = 319). The sensitivity of RBT and FPA in detecting low Brucella titres were evaluated in paired sera (n = 34). A logistic regression model was constructed to predict cattle test result in FPA using RBT as the main predictor and incorporating bio-data and animal history. There was 79.3% agreement between the RBT and FPA (Kappa = 0.59; Std error = 0.05; p = 0.000) and a high correspondence between high RBT scores and positive FPA results suggesting that sera with high RBT score may not require confirmation with tests such as competitive-ELISA or CFT. High FPA cut-off points were more likely to miss animals with low antibody titres. The RBT had a reduced ability in detecting low antibody titres compared to the FPA. FPA test interpretation was improved if a priori information, such as sex and age was used. Under the challenging disease surveillance conditions prevailing in rural Africa, field-testing methods that are sensitive and specific; allow single animal contact, low technical skills in data interpretation are suitable.
authors.affiliation: Department of Disease Control, University of Zambia, Lusaka, Zambia. jbwalya@lycos.com
authors.forename: J B
authors.initials: JB
authors.lastname: Muma
authors.forename: A
authors.initials: A
authors.lastname: Lund
authors.forename: K
authors.initials: K
authors.lastname: Nielsen
authors.forename: G
authors.initials: G
authors.lastname: Matope
authors.forename: M
authors.initials: M
authors.lastname: Munyeme
authors.forename: K
authors.initials: K
authors.lastname: Mwacalimba
authors.forename: E
authors.initials: E
authors.lastname: Skjerve
mesh_terms: D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D002002:Brucella / Q000302:isolation & purification*; D002006:Brucellosis / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D016231:Fluorescence Polarization Immunoassay / Q000662:veterinary; D008297:Male; D012372:ROC Curve; D012395:Rose Bengal / Q000737:chemistry; D012424:Rural Population; D012680:Sensitivity and Specificity; D015024:Zambia / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial; D012395:Rose Bengal